A conventional electric power plug provided with tracking resistance is described in the Japanese Patent 3,327,093. The described electric power plug is of a construction that connecting terminal members or blades are inserted in the thermosetting resin and are connected at its bottom portion to power cords by caulking. The plug body is made of polyvinyl chloride material or the like. The connecting terminal members are provided with gap fillers or sleeves for wrapping or covering the roots of the connecting terminal members. When the resin such as polyvinyl chloride material or the like for making the plug body is injected or inpoured into die assembly, the gap fillers are made simultaneously with the plug body by inflow of the resin through connecting terminal inserting hole.
Since at the conventional power plug the surface of thermosetting resin is exposed to the front surface of the plug body, the thermosetting resin easily gets out of the plug body. In order to prevent the thermosetting resin from getting out of the plug body, the thermosetting resin is required to be provided with a relatively long leg portion which extends into the plug body. Although the gap fillers are made by inflow of the resin through connecting terminal inserting hole when the resin such as polyvinyl chloride material or the like is injected into die assembly, it is very difficult to mold or form a thin gap fillers by that step, and therefore it is believed that it is very difficult to mold a thin gap fillers simultaneously with the perfect molding of plug body.
Therefore, it is an object of the present invention to provide an electric power plug in which sleeves and a core can be integrally molded to prevent the thermosetting resin from getting out of the plug body.
It is the other object of the present invention to provide a method of producing an electric power plug in which sleeves and a core can be integrally molded to prevent the thermosetting resin from getting out of the plug body.